Doesn't build with Vala 0.21.1, "close" conflict in GTK 3.10: Closes #7295, Closes #7254

The number of deprecated classes and methods in GTK 3.10 is too much work
simply to get Shotwell to compile, so that's been moved to #7301.  This
patch fixes some "hard" compile errors and disables warnings for deprecated
symbols.
Merge branch 'master' of git://yorba.org/shotwell